In a Free Electron Laser (FEL) that uses an energy recovering LINAC as an energy source, Terahertz (THz) radiation may be generated at the first bending dipole downstream of the wiggler. Unfortunately, without absorption or smoothing, the irregular shape of the radiation, further distorted by multiple bounces down the inside surface of the beam tube, distorts the minor downstream of the wiggler, causing the optics to degrade and the FEL to lose power.
Accordingly, in high power Free Electron Lasers, there is a need for a device that manages Terahertz radiation and minimizes the distortion of any downstream minors.